Symposium on Pediatric and Adolescent Gynecology
Gonadal Dysgenesis and Its Variants Paul G. McDonough, MD.*
The relationship of primary amenorrhea, webbing of the neck, cubitus valgus, short stature, and sexual infantilism was noted in 1938 by Turner who believed that the primary defect was pituitary in origin. 16 The term gonadal dysgenesis was designated by Grumback, Van Wyck, and Wilkins in 1955 in deference to the rapid expansion of the phenotypic variations seen with rudimentary streak gonads. 5 In the last decade, as a result of developments in human clinical cytogenetics and improved methods of gonadal visualization, a wide variety of karyotypic and phenotypic variations have been described in association with gonadal dysgenesis. The purpose of this article is to bring into focus the infinite variety of phenotypes seen with rudimentary streak gonads, the essential laboratory aids in diagnosis, and the common pitfalls encountered in the management of such patients. Economy is the keynote and stress will be placed upon utilizing to a maximum those studies that are simple, inexpensive, and available to clinicians in the average hospital setting. Physicians generally have no difficulty in recognizing the classical Turner's syndrome, thus more time will be devoted to discussing those clinical variants which may pose difficult and confounding diagnostic problems for the clinician. The simple recognition of these variants and expedient methods of diagnosis will be described. One cannot neglect those recent advances in radioimmunoassay of serum follicle-stimulating hormone (FSH), luteinizing hormone (LH), diagnostic use of gonadotropins, and pediatric-adolescent laparoscopy, which are of considerable value in the diagnosis and management of patients with rudimentary streaks. The utility of these recent additions to our diagnostic armamentarium will be evaluated as to their practical scope and reliability in everyday clinical medicine. Ford's discovery in 1959 that patients of the Turner phenotype possess a single X sex chromosome (45,XO) has been the lift-off point for subsequent cytogenetic and more intensive clinical evaluation of these patients throughout the last decade. 3 Since that time a spectrum of sex chromosome karyotypes ranging from 45,XO to 46,XX and 46,XY have * Associate Professor of Obstetrics and Gynecology; Chief of Gynecology, Endocrine-Genetics Unit, Medical College of Georgia, Augusta, Georgia
Pediatric Clinics of North America- Vol. 19, No.3, August 1972
been described in association with the rudimentary or neuter gonad. 2 ,4 The clinical ledger on the other hand records individuals with innumerable somatic anomalies and other individuals quite void of any evidence of a somatic defect except for the rudimentary gonad. The observation that rudimentary streaks may even occur in patients of normal or tall stature has been made over and over again in the last decade. 4 ,5 Such patients devoid of somatic anomalies are spoken of as cases of "pure gonadal dysgenesis." They are "pure" in the sense that they have one solitary anomaly, namely the rudimentary streak gonad. The confusion has been further compounded by more recent reports of individuals with rudimentary streak gonads who have exhibited degrees of ovarian function ranging from development of secondary sex characteristics to sporadic menses, and in two rather well-documented instances, pregnancy. I, 8, 9, 13 The wide range of karyotypic and phenotypic variations seen in these individuals has baffled the experts and confounded even further our understanding of normal gonadal morphogenesis. Such variability in phenotypes leaves us with only one common denominator in gonadal dysgenesis, namely the possession of rudimentary streak or neutral gonad. This simplistic definition is quite acceptable as long as one realizes that in certain instances such streaks may manifest endocrine function and in two reported instances exocrine function as attested by the two reported instances of pregnancy in such individuals.!' 13 The explanation for ovarian steroid secretion in some of these individuals has been elucidated by the fine work of Singh and Carr.15 Their studies with early 45,XO human embryos clearly indicate that germ cells do migrate into the genital ridge in such patients. Prior prevailing opinion was that the neuter gonad was basically the result of a failure of germ cell migration which in turn was due to the primary genetic privation. The work of Singh and Carr seems to substantiate germ cell migration in such patients; however, there is a rapid attrition of primary oocytes during the latter part of intrauterine and early neonatal life. The cause of this degeneration is not clear; however, in individuals who are monosomic for the X chromosome it is conceivable that in the absence of a chromosomal mate or suitable pairing that spontaneous degeneration of the primary oocytes may be expedited. Obviously such a biological process is not an all or none phenomenon and in certain individuals a residual of primary oocytes may remain and be active in steroid secretion at the time of puberty. Such a small bastion of primordial follicles may provide varying amounts of estrogen and thus we may see varying degrees of development of secondary sex characteristics and menses in such individuals. The rather well-documented reports of pregnancies in two patients monosomic for the X chromosome is within the realm of reason when one considers the unlikely but still possible chance of sporadic ovulation occurring in rare instances. Our attempts to decipher the wide range of clinical phenotypes seen in gonadal dysgenesis has thus been aided by this fundamental information regarding germ cell migration in these individuals.
GONADAL DYSGENESIS AND ITS VARIANTS
CLINICAL ASPECTS The wide variety of clinical phenotypes makes it apparent that the patient with gonadal dysgenesis may present in the classical fashion as a Turner's syndrome, or may manifest normal or unusually tall height ranges. To these three clinical categories may be added those patients who may present with androgenic manifestations and lastly the rare occurrence of faInilial gonadal dysgenesis. Short Stature The patients of short stature, at this stage of our knowledge, still constitute the most common clinical phenotype encountered with rudimentary gonadal streaks. In this classical group one will find the highest incidence of extragenital anomalies and the greatest quantitative privation of genetic material. 4 In attempting to evaluate the importance of extragenital anomalies in these patients one may encounter some difficulty. This is due to observer variability and also to the fact that such somatic anomalies as cubitus valgus, high palate, shield chest, and neck webbing are observable in normal individuals and also in individuals with other systemic genetic diseases. In thinking of the patient with gonadal dysgenesis, one should consider the short stature as simply another somatic anomaly resulting from the privation of genetic material. The vast majority of patients who are short in stature, that is below five feet or sixty inches in height, will have an XO sex chromosome constitution. Thirty to 40 per cent of the short patients with rudimentary streaks will exhibit some form of sex chromosomal mosaicism with one cell line usually being XO.4 A clue as to the presence of mosaicism will be discussed later in our evaluation of one of the valuable diagnostic techniques, namely the buccal smear. In general the shortness of stature in these individuals is due to the loss of one X chromosome and more specifically the short or p arm of the deleted X chromosome. Although generalizations in this field are always subject to some exceptions, one can say that the greater the privation of genetic material, the higher the incidence of somatic anomalies seen in these individuals. Precisely how does one diagnose and manage the classical Turner's syndrome with short stature and major or minor somatic anomalies? Usually the clinical impression of Turner's syndrome is quite readily learned from the phenotypic appearance of the patient. Actually many of these patients are being detected much earlier in life because of the compulsion on the part of pediatricians to perform a buccal smear on every child with growth retardation. Needless to say a careful physical examination is performed on these children. Many times in our enthusiasm to establish the diagnosis of a rudimentary streak we overlook the more important obligation which is to rule out serious cardiovascular-renal anomalies in these patients. In such children one should first perform a buccal smear for the presence or absence of a chromatin mass. If the child is short in stature, of the Turner phenotype, and has a negative buccal smear, then one can infer that she is 45,XO or monosomic for the X
chromosome. Although some may disagree, I do not see any reason to perform expensive chromosomal karyotyping of peripheral blood when the clinical features and buccal smear correlate so readily. An intravenous pyelogram is performed on these children to rule out any renal anomaly and then they are referred to a cardiologist for a careful cardiovascular evaluation. A hand film for bone age is taken and in some instances blood levels for serum FSH and LH are obtained. The latter are not a necessity in the hitherto described phenotype. Over 6 years ago I routinely performed pelvic pneumoperitoneum for final diagnostic confirmation on these children; however, I have found it to be an unnecessary study in the child with a negative buccal smear and under 60 inches in height. Bioassay measurements of total urinary gonadotropins have proven to be unreliable in these subjects unless the result is an unusually high value. This bioassay procedure based upon uterine-weight augmentation in the immature mouse is quite unpredictable, and, contrary to popular opinion, difficult to interpret properly when the resultant values are low or normal. In short, diagnosis in the subject of the Turner phenotype requires a negative buccal smear and a careful cardiovascular-renal evaluation for extragenital anomalies. The rare exception to the foregoing statement will be discussed under the deceptive variants of gonadal dysgenesis. Normal Stature There is increasing realization especially on the part of the gynecologist that patients who are of normal stature, devoid of somatic anomalies, and occasionally even with manifest menses may have rudimentary streak gonads. 8 The physical examination many times affords no clue to the diagnosis. However, if one looks closely one may observe two things, namely that the girl is usually taller than her siblings and that pubic hair, though present, may be relatively scant. Normal stature here is classified arbitrarily as a height range from 62 to 65 inches. Most of these patients of normal stature will present with sexual infantilism and primary amenorrhea. Some of them may give a history of an abbreviated menstruallife ranging from 6 months of menses following menarche to sporadic menses for a period of 6 or 7 years. B • 9 The first step in the diagnostic approach to the individual of normal stature is the buccal smear. Individuals who are in the upper height ranges usually have a normal buccal smear, demonstrating 30 to 35 per cent single Barr bodies in 100 buccal cells. In general this is indicative of a normal 46,XX sex chromosome karyotype. Other individuals at the lower end of the height spectrum may have quantitatively low Barr body counts in the range of 4 to 6 per cent single Barr bodies per 100 cells, and this suggests mosaicism or two cell lines. One of these cell lines is usually consistently 45,XO whereas the other cell line may be a normal 46,XX. Bone age for evaluation of physiologic age is invariably done in these individuals and it does help to indicate whether gonadal steroids have been elaborated by the "inert gonad." Some discussion of this will be covered under the essential diagnostic aids and their interpretation. Gonadal visualization is a manifest necessity in those females who
GONADAL DYSGENESIS AND ITS VARIANTS
are phenotypically normal and have a normal 46,XX sex chromosome karyotype. In such individuals preliminary serum estimations of FSH and LH can be performed prior to pelvic pneumoperitoneum or endoscopy. In the last analysis, the final diagnosis depends upon visual documentation of the rudimentary streak. Tall Stature Individuals with gonadal dysgenesis who are over 65 inches in height fall into two karyotypic categories. One such category is the individual who is tall and has a normal 46,XX sex chromosome karyotype. One might say that she is genetically or, to be more precise, chromosomally competent and gonadal visualization is essential for diagnosis. There is another form of gonadal dysgenesis in which the subject is unusually tall, usually 5 feet 9 inches to 6 feet in height, and has primary amenorrhea, sexual infantilism, and a negative buccal smear. In these individuals, if the Mullerian system or uterus is evident on pelvic examination, then one can safely assume that the other sex chromosome is a Y chromosome and this is an example of gonadal dysgenesis with an XY sex chromosome karyotype. Some authors refer to such cases as "testicular dysgenesis" insomuch as the gonad genetically may have been destined to be a testicle. These individuals do require gonadal visualization, not necessarily for diagnosis, but simply to assess the rudimentary streak for the presence of a neoplastic tumor. The presence of the Y chromosome seems to predispose to neoplastic changes within rudimentary streak gonads and usually requires therapeutic extirpation.7. 10. 14 In brief, XY gonadal dysgenesis is not well understood, however it is conceivable in these individuals that teratogenic factors may interfere with germ cell migration during early intrauterine life and leave a neuter or neutral gonad. Consonant with the classical experiments of Jost, such individuals will develop a normal Mullerian system and normal female external genitalia. 6 Blockage of germ cell migration is perhaps an oversimplified explanation since we do see familial XY gonadal dysgenesis which makes a recurring teratogenic factor a rather untenable hypothesis. 1 Androgenic This group of patients with gonadal dysgenesis are worthy of brief mention. The diagnosis should be evident from the clinical picture and the buccal smear. The pediatrician is usually presented with a child short in stature, with or without somatic anomalies, clitoral enlargement, separate urethral and vaginal orifices, and a negative buccal smear. This picture is all quite compatible with asymmetrical or mixed gonadal dysgenesis and a 45,XO/46,XY sex chromosome mosaicism. The shortness of stature is due to the presence of the 45,XO sex chromosome cell line. These individuals have a normal Mullerian system; however, one intraabdominal gonad is a testicle and the other is a rudimentary fibrous streak. 12 Therapeutic extirpation of these intra-abdominal gonads and clitorectomy is indicated at an early age. Such an individual is depicted in Figure 1. This child is much shorter than one would anticipate from
Figure 1. A, Five year old girl who is in lower ten percentile for growth. B, Large phallus, urogenital sinus with
proximal separate urethral and vaginal orifices. (From McDonough, P. G., and Simmons, R. G.: Obstet. Gynec.,37:368, 1971, reproduced with permission.)
her chronological age, and in addition one notices the ambiguous external genitalia. Apart from her shortness of stature the only other minor somatic anomaly was strabismus. The diagnosis was made from the clinical phenotype and buccal smear prior to karyotyping of peripheral blood. The presence of a normal Mullerian system, left streak gonad, and right testicle was documented by pelvic pneumoperitoneum. The Y chromosome and testicle dictated therapeutic extirpation of the adnexal structures.
Familial In certain instances rudimentary streak gonads have been seen in siblings. In those instances where gonadal dysgenesis has been reported in siblings these children are of a normal 46,XX or 46,XY sex chromosome karyotype.!, 4, 5 They are invariably normal in stature, have primary amenorrhea, sexual infantilism, and usually lack somatic anomalies. Familial gonadal dysgenesis still remains somewhat enigmatic. It may be that these individuals have a single point mutation on one of the sex chromosomes or a portion of one of the sex chromosomes is missing but undetectable by present methods of chromosomal karyotyping. Using
GONADAL DYSGENESIS AND ITS VARIANTS
other tracer genes, there have been one or two instances in the literature suggesting that familial gonadal dysgenesis may be transmitted as an autosomal recessive gene; however; this remains to be proved. Obviously the proof of such a hypothesis would require evidence of vertical transmission of familial XX or XY gonadal dysgenesis. ReceQtly vertical transmission has been reported by a group from New Zealand. 2
APPROACH: PERTINENT LABORATORY AIDS AND THEIR INTERPRETATION
Since the patient with rudimentary streaks may be normal in appearance, devoid of somatic anomalies, and even possess some menstrual function, it behooves the clinician to examine closely and use wisely the valuable diagnostic aids which are available to assist us in the diagnosis of gonadal dysgenesis. These aids become quite valuable if we are going to detect the patient who is to all appearances normal on physical examination, the patient who may have subtle associated cardiovascular-renal anomalies, and those patients who are prone to develop tumors in their dysgenetic gonads. There are five essential diagnostic aids which if used wisely and interpreted properly should provide the clinician with an accurate diagnosis of rudimentary streak gonads. In our institution over the past seven years we have found these aids to be most essential and fortunately very economical. They are the buccal smear, anteroposterior film of the pelvis (to include the iliac epiphysis), intravenous pyelogram, gonadal visualization, and vaginal smear for endocrine evaluation. Of these five we have found the first three coupled with gonadal visualization to be the pivotal studies in the establishment of the proper diagnosis. Buccal Smear The buccal smear for detection of a chromatin mass representing the genetically inactive and late replicating X chromosome has been the most valuable study in our hands. By careful interpretation of the buccal smear one is able in most instances to obviate the need for expensive chromosomal karyotyping of peripheral blood. Whereas most institutions scan the buccal smear simply for the presence or absence of a chromatin mass, We search readily for each of the following characteristics from which we can obtain valuable additional information: (chromatin mass and Barr body are used here interchangeably). (1) presence or absence of a chromatin mass, (2) number of chromatin masses per cell, (3) number of cells per 100 containing a single or more than one chromatin mass, and (4) size of the chromatin mass in relation to a control buccal smear. Generalizations in this area are always subject to some exceptions but in general if a buccal smear exhibits over 30 per cent of the cells with a single Barr body then we can assume that the patient has a normal
46,XX sex chromosome karyotype. We believe that evaluation of the buccal smear with respect to the four foregoing attributes to be so valuable and economical that it justifies some detailed discussion with respect to each of these four findings. PRESENCE OR ABSENCE OF A BARR BODY. Patients portraying the clinical picture of the classical Turner's syndrome and possessing a buccal smear devoid of any Barr bodies is quite certain evidence that the sex chromosome karyotype is 45,XO. I would like to stress that the essential nexus here is the correlation of the short stature with the negative buccal smear, indicating an individual who is monosomic for the X chromosome. One might postulate that the other sex chromosome is a Y chromosome, but this is true only if the individual is tall in stature. As described previously under individuals of short stature with a negative buccal smear we do not feel that it is necessary to proceed any further to establish the diagnosis except to stress the importance of a careful evaluation of the cardiovascular-renal system in these individuals. This point cannot be overemphasized since these are precisely the individuals, monosomic for the X chromosome, who do have the serious cardiovascular-renal anomalies such as coarctation of the aorta which may shorten their life span. NUMBER OF BARR BODIES PER CELL. In some instances an alert cytogeneticist will inform you that a certain percentage of the cells, 5 or 6 per cent for example, possess two Barr bodies. From such priceless information you can infer that one cell line is 46,XXX and the other cell line is presumably 45,XO. In other words the buccal smear enables you to immediately suspect the existence of a 45,XO/4 7 ,XXX sex chromosome mosaic. As is evident from previous studies in the literature, those patients who have abnormal sex chromosome karyotypes will have rudimentary
Figure 2. Illustrative nucleus from buccal cell demonstrating two normal-sized chromatin bodies. (FTOm McDonough, P. G., Byrd, J. R., and Mahesh, V. B.: Fertil. Steril., 20:451,1969, reproduced with permission.)
GONADAL DYSGENESIS AND
streak gonads. 4 A buccal smear of this type is seen in Figure 2. Some such individuals with sex chromosome mosaicism may have short menstruallives and present with secondary amenorrhea. The 18 year old girl depicted in Figure 3 is a 45,XO/4 7 ,XXX sex chromosome mosaic who had menarche at 13 years of age and subsequently had 7 months of spontaneous menses prior to her presenting complaint, namely secondary amenorrhea. The prompt recognition that a small percentage of her buccal cells possessed two chromatin masses obviated the necessity for expensive and time-consuming urinary-steroid studies. NUMBER OF CELLS PER 100 CONTAINING A SINGLE OR MORE THAN ONE CHROMATIN MASS. One should always insist upon quantitation of the buccal smear. If a single chromatin mass is present, is it present in over 30 per cent of the cells? If on repeated buccal smears the single Barr body is present but only in a small percentage of the cells, then again one should suspect a sex chromosome mosaicism of the 45,XO/46,XX variety. Such an inferred mosaic sex chromosome karyotype would indicate rudimentary streak gonads. Quantitation may be a relative thing subject to considerable variation from laboratory to laboratory and requires extensive karyotyping for accurate documentation. In such instances the clinician rather than expend money and time for cytogenetic studies may prefer to proceed immediately to gonadal visualization.
Figure 3. Eighteen year old girl with 6 months of menses and 45,XO/47,XXX sex chromosome mosaicism: (From McDonough, P. G., Byrd, J. R., and Mahesh, v. B.: Fertil. Steril., 20:451, 1969, reproduced with permission.)
SIZE OF CHROMATIN MASS IN RELATION TO A CONTROL BUCCAL SMEAR. Reference was made earlier to the fact that all patients who are short of stature will usually have a negative buccal smear. The one confusing situation which is an exception to this rule is the patient who is short in stature with somatic anomalies and seemingly has a "normal buccal smear-sex chromosome constitution." If one sees a patient who seems to possess all the features of the Turner phenotype yet the lab consistently reports a normal 46,XX sex chromosome karyotype then be highly suspicious that you are dealing with an isochromosome. One will notice in Figure 4 two buccal smears, one demonstrating a normal size chromatin mass, and the other demonstrating a chromatin mass considerably larger than the control smear. In the subsequent figure, Figure 5, you see the karyotype from peripheral blood on this individual. You will notice that the second X chromosome is large and the short upper arm is replaced by an arm identical in length to the large lower or q arm. This is a situation in which the upper short arm or p arm of the X chromosome has been lost and there has been a reduplication of the long arm. These individuals, though they seem to possess excess chromosomal or genetic material, in fact are deficient in the short or p arm of one of the X chromosomes. It is precisely this privation that contributes to their shortness of stature. Unless the cytogeneticist is alerted from the clinical description to the possibility of an isochromosome it is very easy, even in the best hands, to report this as a normal karyotype.
Bone Age The second essential study which should be performed on all patients with gonadal dysgenesis and actually in fact on all patients with primary amenorrhea is a hand film for bone age and an anteroposterior film of the pelvis. Physiologic or bone age in these children progresses satisfactorily
B Figure 4. A, Chromatin mass in control buccal' smear. B, Large chromatin mass due to presence of isochromosome X.
GONADAL DYSGENESIS AND ITS VARIANTS
11111111, --------0 .. •• .. GAttf' ----0---II
Karyotype illustrating large isochromosome X.
until expected endocrine menarche, at which time it stops. This is usually in the vicinity of chronologic ages 12 to 13 years. Bone age dates the onset of gonadal failure. An anteroposterior film of the pelvis is taken in these patients for two reasons. The iliac epiphysis undergoes ossification through the influence of gonadal steroids. Its appearance radiologically, therefore, is coincident with the secretion of gonadal steroids, and its ultimate infusion is contingent upon the continued elaboration of ovarian hormones. In individuals with rudimentary streaks and absence of gonadal steroids this epiphysis will not undergo ossification and therefore will not be apparent on roentgen examination of the pelvis. On the other hand if the epiphysis has begun to ossify, it indicates that ovarian steroids have been or are being released by the gonad. Under normal circumstances in an adolescent girl the iliac epiphysis begins to appear or calcify within 6 months of endocrine menarche, grows lateral to medial, and undergoes fusion at approximately 21 years of age. It is therefore a very good indicator of the release of gonadal steroids. Any abrupt cessation in its ossification pattern indicates that ovarian steroid function has stopped or is waning. In some instances it is possible to date the onset of a pituitary tumor in an adolescent girl by the degree of ossification and fusion of the iliac epiphysis. It is a very good prognostic indicator as to the onset of menarche in a child with physiologic delay. The second reason for obtaining a preliminary film of the pelvis in patients with gonadal dysgenesis is to search for evidence of calcification within the region of the rudimentary streak. One of the two most com-
Figure 6. Area of floccular calcification evident in region of right streak. (From McDonough, P. G., Greenblatt, R. B., Byrd, J. R., and Hastings, E. V.: Obstet. Gynec., 29:54, 1967, reproduced with permission.)
mon tumors occurring in rudimentary streaks is the gonadoblastoma which characteristically undergoes calcification. Figure 6 demonstrates the calcific densities seen in this tumor. Many times these neoplastic enlargements are evident by roentgen calcification long before they are felt. The anteroposterior film of the pelvis is not only a preliminary study in our clinic, but it is also repeated at the time of 6 month and yearly follow-ups of patients with gonadal dysgenesis in order to detect unsuspected neoplastic tumors in the ridge. Obviously in patients who present with primary amenorrhea, the film of the pelvis may be useful in the screening for calcifications within pelvic tuberculosis. Evaluation for Cardiovascular-Renal Anomaly The third essential diagnostic, and in a sense therapeutic, aid is careful evaluation of the patient with gonadal dysgenesis for I.::ardiovascular-renal-skeletal anomalies. This usually includes an intravenous pyelogram and also careful evaluation of the cardiovascular system. Although the interest of the physician may be centered upon the gonad, we feel that the more important focus of attention should be the cardiovascular anomalies which may pose a serious threat to the life
GONADAL DYSGENESIS AND ITS VARIANTS
pectancy of these patients with gonadal maldevelopment. Too often we see patients with an established diagnosis of gonadal dysgenesis in whom coarctation of the aorta or a severe renal anomaly has not been detected because of omission of these essential studies. Vaginal Smear Vaginal smear for endocrine effect is performed in certain patients with gonadal dysgenesis. Usually inspection of the vaginal mucosa and the infantile external genitalia give all the evidence one needs that this patient has not been or is not releasing ovarian steroids at the time of examination. In some patients who have attenuated menstrual histories and present with amenorrhea, the vaginal smear may be quite important in detecting the complete absence of gonadal steroid function and the necessity for a more complete investigation into the etiology of this deficiency. Most of our patients with gonadal dysgenesis and secondary amenorrhea have been picked up because of the alertness and high index of suspicion on the part of our house officers in performing vaginal smears for endocrine effect on all patients with abbreviated menstrual histories. A castrate smear is certainly a warning signal that demands explanation why a female in the reproductive age group is not secreting ovarian steroids. Gonadal Visualization Gonadal visualization in many instances is a necessary and crucial evaluation. There are some patients with pure gonadal dysgenesis who
Figure 7. Pelvic pneumoperitoneum in 18 year old with rudimentary streaks. Arrows indicate streak gonads. V, uterus. B, bladder.
are normal in stature, have no somatic anomalies and even have a normal sex chromosome karyotype. The diagnosis of rudimentary streaks cannot be docuIp.ented in these patients unless some form of gonadal visualization is performed. We have found pelvic pneumoperitoneum to be quite adequate in demonstrating the presence or absence of ovarian tissue. Such a pelvic pneumoperitoneum is evident in Figure 7. We have used pelvic pneumoperitoneum in ages ranging from 16 months through the reproductive age group. Culdoscopy or endoscopic puncture of the posterior cul-de-sac with the patient in the knee-chest position has been used also for the diagnosis of gonadal dysgenesis. However, in those individuals who have infantile genitalia, the available space in the posterior cul-de-sac is somewhat limited and may render this technique in inexperienced hands slightly hazardous. The advent of fiber optics and cold light illumination has led to a resurgence of interest in the use of the pelvic laparoscope. In smaller infants and children, we utilize a laparoscope which is 4 to 5 mm. in diameter as opposed to the 10 mm. telescope which is used in adults. These children are usually examined under general endotracheal anesthesia. I would like to stress that gonadal visualization is not always a necessity, especially if one is dealing with an individual of the classical Turner phenotype who possesses a negative buccal smear.
CONFIRMATORY AND SUPPLEMENTARY STUDIES
The five aforementioned studies are the essential and crucial ones in most instances and should establish the diagnosis of gonadal dysgenesis. It is well to comment here on certain studies which may be confirmatory and supplementary to the essential diagnostic aids. Determination of total urinary gonadotropins, commonly misdesignated as urinary FSH, has been performed as a diagnostic tool for a number of years in patients with gonadal dysgenesis. Unfortunately, this is a bioassay procedure based upon uterine weight augmentation in the immature mouse and has many limitations. Experience with this assay in patients with gonadal dysgenesis is that, more often than not, the values are low or normal, rather than the anticipated high values for total urinary gonadotropins. There are many reasons why this is so, and they have to do principally with the methodology involved in the bioassay procedure for urinary gonadotropins (FSH(LH). In attempting to extract urinary gonadotropins and render the extract nontoxic to the immature mouse, it is many times unfortunate that the biological activity of the extract is destroyed. On the other hand, if one attempts to preserve biological activity the extract itself may prove quite toxic to the mouse, and he may not survive or his response to the injected material may be quite difficult to interpret because of the stressful situation under which the end point of the assay is being measured. The other limitation is that it seems to require optimal ratios of FSH and LH to evoke a uterine weight augmentation in the animal. Lastly, it would appear from recent clinic studies that gonadotropins in urine probably represent only 20 to 25 per
GONADAL DYSGENESIS AND ITS VARIANTS
cent of the gonadotropins that are actually being secreted by the pituitary. Changes in structural configuration of urinary gonadotropins may explain the disparity between serum and urine values for these trophic hormones. All of this seems to explain why in the past measurements of total urinary gonadotropins in patients with gonadal dysgenesis have not consistently exhibited the anticipated high values. More recently, methods utilizing a double antibody single isotope technique have been developed for the serum assay of FSH and LH. We have found these to be quite reliable in patients with primary ovarian failure. In general, normal nonluteal values for serum FSH and LH are approximately 4-5 mIU /ml. In patients with gonadal dysgenesis or primary ovarian failure, we find that FSH values are 100 mIU/ml. and LH values are usually in the range of 75 mIU /ml. This assay simply requires 5 ml. of clotted blood and high values are diagnostic of ovarian failure. We customarily perform routine blood sugar, protein-bound iodine, and cholesterol determinations on patients with gonadal dysgenesis. This is simply in deference to a reported incidence of diabetes mellitus in these patients. The thyroid evaluation is carried out insomuch as some individuals, especially those with isochromosomes, may have autoimmune antibodies with secondary hypothyroidism. It is rare that urinary assays for 17-ketosteroids and 17-ketogenic steroids are necessary in patients with gonadal dysgenesis. However, it is extremely important to realize that some of these patients may have poor adrenal function which becomes manifest only under stress. One must warn the clinician who is contemplating surgery on a patient with gonadal dysgenesis that he should be very alert to anticipate the signs of adrenal insufficiency and treat them promptly. In certain instances, chromosomal karyotyping may be necessary in the patient with gonadal dysgenesis. Contrary to most articles that you read where a great deal of emphasis is put upon karyotyping of peripheral blood, I have put most of my emphasis on the interpretation of the buccal smear and gonadal visualization. Chromosomal karyotyping of peripheral blood is of greatest value in those individuals who have a low quantitative count (m the buccal smear and in whom mosaicism may be suspected. It is obviously very important also in individuals in whom you may suspect an isochromosome as has been described previously. One must carefully balance the expense of chromosomal karyotyping and its reliability with respect to diagnosis versus the expense of gonadal visualization when the diagnosis is in question or uncertain. In rare instances, gonadal visualization may reveal small ovaries but seemingly with some evidence of primordial follicles. In certain instances, we have used human menopausal gonadotropin to test the competency of these ovaries. A positive response to exogenous human menopausal gonadotropin as evidenced by changes in the vaginal smear and subsequent withdrawal menstrual period is evidence that these ovaries are capable of being activated. It is essentially a diagnostic test to differentiate between hyper gonadotropic hypogonadism versus hypo gonadotropic hypogonadism.H
VARIANTS: PITFALLS FOR THE CLINICIAN It is precisely at this point that we should stress those variations of gonadal dysgenesis which may sometimes be confusing and provide pitfalls for the unwary clinician.
Gonadal Dysgenesis with Excessive Estrogen Production One must be concerned if one sees a patient who is short, monosomic for the X chromosome, and yet paradoxically has evidence of excessive estrogen secretion as evidenced by excellent breast development and even atypical vaginal bleeding. One should be alert to the possibility of an estrogen-producing tumor in the rudimentary ridge. Such a patient is depicted in Figure 8. This patient, though short in stature, had normal thelarche, adrenarche, and menarche, and then began to exhibit atypical vaginal bleeding requiring endocrine therapy for control. Because of the suspicion of an estrogen-producing tumor in the rudimentary ridge, diagnostic culdoscopy was performed and revealed cystic enlargement of the
Figure 8. 45,XO untreated 15 year old female with irregular bleeding.
GONADAL DYSGENESIS AND ITS VARIANTS
Figure 9. Upper specimen demonstrates cystic enlargement (arrow) of the streak (functional theca-lutein cyst). (Small dark arrows depict streaks.)
proximal portion of the rudimentary streak. At laparotomy, this proved to be a large functional theca-lutein cyst. This was subsequently extirpated with both ridges and they are depicted in Figure 9. The axiom here is that any patient with gonadal dysgenesis with evidence of undue estrogen production should have gonadal visualization performed. Excessive Androgen Production One should always be suspicious of the variant exhibited by the patient with gonadal dysgenesis who seems to have androgen overproduction as evidenced by excessive pubic hair. Individuals with gonadal dysgenesis will have pubic hair, but it tends to be somewhat scant. Patients who exhibit evidence of excessive androgen production are high risk candidates for an androgen-producing tumor in the ridge, and this is usually a gonadoblastoma. Such a patient is depicted in Figure 10. This patient had a 45,XO/46,X fragment sex chromosome constitution with a negative buccal smear, and the fragment is presumed to be a Y chromosome. At laparotomy, she had a gonadoblastoma in her rudimentary streak, and this was evident on the anteroposterior film of the pelvis by the typical pattern of floccular calcification. Evidence of excessive androgen production and/or a suspected Y chromosome is one of the indications for prophylactic therapeutic extirpation of rudimentary streak gonads.7. 10. 14
Tall Patient with Gonadal Dysgenesis The third situation which may be somewhat confusing to the clinician is the patient who is tall in stature, close to 6 feet, with primary
Figure 10. 21 year old female with primary a m e norrhea and gona doblas toma in a streak gon a d. (From McDonough , P. G. , Greenblatt, R. B., Byrd , j . R. , and Hastin gs, E. V.: Obste t. Gynec. , 29:54, 1967, reproduced with permission.)
Figure 11. 21 year old fe male with gonadal dysgenesis and 46,XY sex chromosome karyotype (es trogen therapy prior to photo).
GONADAL DYSGENESIS AND ITS VARIANTS
amenorrhea, sexual infantilism, and a negative buccal smear. As you know, patients who are monosomic for the X chromosome are almost invariably short in stature. If one sees a patient who is tall, female phenotype such as depicted in Figure 11, and with a negative buccal smear, then one can infer that the other chromosome is a Y chromosome, and this is an example of gonadal dysgenesis or "testicular dysgenesis." These individuals seem to grow to rather excessive heights because they are chromosomally competent, and in the absence of gonadal steroids their epiphyses remain open with unrelenting linear growth. Gonadal Dysgenesis with Normal Stature, Normal Secondary Sex Characteristics and Normal Sex Chromosomes Patients with "pure gonadal dysgenesis" will be more commonly recognized as we realize their prevalence in the population at large. In order to document the diagnosis of rudimentary streak gonads in these individuals gonadal visualization is required. Many of these patients will present with secondary amenorrhea. Isochromosome A fifth variant of gonadal dysgenesis is those individuals who are short in stature, have a Turner phenotype, but yet seem to have a normal buccal smear and a normal sex chromosome karyotype reported from the laboratory. It is imperative, if gonadal dysgenesis is suspected, that the cytogeneticist repeat the karyotype in order to try to ascertain the presence of an isochromosome. If this is not feasible within your laboratory situation, then one should proceed immediately to gonadal visualization. Gonadal Dysgenesis with Menses Secondary amenorrhea, especially when the menstrual life has been short, is now an indication for the performance of a buccal smear. The same also applies to those individuals who are short in stature at 11 or 12 years of age but yet have some evidence of breast buds or ovarian function. It is still possible that these individuals may be short in height because of a sex chromosome abnormality in spite of the release of a limited amount of ovarian steroids. In other words, it is axiomatic, regardless of development of secondary sex characteristics, to perform a buccal smear on all individuals who are short of stature for their given age. Adrenal Hypofunction Some patients with gonadal dysgenesis in spite of urinary steroid values may exhibit adrenal hypofunction under situations of stress. Unfortunately, in some instances-especially postoperatively-this adrenal insufficiency syndrome is recognized too late and belated therapy with adrenal steroids is unsuccessful. Fertility There are two reported instances of fertility or pregnancy in patients with XO gonadal dysgenesis. I • 13 Both cases are well-documented except for the absence of gonadal visualization in one. I suspect that this phenomenon may be more frequent than is reported, as I have had several in-
stances of personal communication where physicians maintain that they have seen rudimentary streak gonads at the time of Cesarean section.
RESPONSIBILITY TO THE PATIENT Our prime responsibility to the patient is to seriously consider and rule out cardiovascular-renal anomalies which may pose a more serious threat to life than her secondary endocrine deficit. Cardiovascular and renal evaluation is always obligatory in these subjects. Our second responsibility to patients with rudimentary streak gonads is continual surveillance for the possibility of neoplastic change in the rudimentary streak. Experience accumulated over the past 5 years seems to clearly indicate that certain individuals with rudimentary streak gonads are at high risk for the development of ridge tumors. These individuals seem to consistently exhibit undue masculinization or have a Y chromosome in their sex chromosome complement. Prophylactic extirpation of rudimentary streaks is therefore advocated in such individuals. Individuals who are not masculinized or do not possess a Y chromosome should be evaluated periodically at yearly intervals with a careful pelvic examination. In addition to the pelvic examination, an anteroposterior film of the pelvis should be obtained to detect any evidence of calcific changes within a rudimentary streak. The two most common tumors occurring in rudimentary streak gonads are gonadoblastoma and dysgerminoma. The gonadoblastoma contains Sertoli cells, Leydig cells, and germ cells, and thus recapitulates the embryonic development of the ovary. The gonadoblastoma is extremely prone to undergo degenerative calcific changes which are readily apparent on x-ray.7 Up until recently, no evidence of metastasis had been reported from a gonadoblastoma. However, recently there have been several reported instances of metastatic neoplasms. 14 In some gonadoblastomas, the germ cell element may predominate and thus they may behave biologically like dysgerminomas. Another important responsibility in the care of the patient with gonadal dysgenesis is the constant awareness of the possibility of adrenal hypofunction especially when these patients are subjected to undue stress such as a surgical procedure. I have seen one postoperative death resulting from a lack of awareness of this potential problem in a patient with gonadal dysgenesis.
THERAPY AND FOLLOW-UP Counseling these patients can be a very delicate matter, requiring a considerable amount of tact on the part of the physician. For young girls who are 12 to 13 years of age, it is important to give them some idea of their final adult height. In many instances, it is helpful to have them meet a patient with gonadal dysgenesis who has been successfully treated. This can be quite helpful regarding reassurance as to the effectiveness of medical therapy in the development of adequate secondary sex characteristics. Unless she should ask, the very young girl is not told
GONADAL DYSGENESIS AND ITS VARIANTS
at the first encounter the fact of her sterility. However, later on when she has adapted to her decreased stature, the fact of her sterility is then explained to her. With this information she is in a better position to plan her future life. Usually when a frank and candid prognosis is given to these patients they are able to accept the future with a considerable amount of equanimity and plan their lives accordingly. Endocrine therapy is initiated at 11 years of age chronologically, and we usually begin with a sequential preparation containing a rather large amount of estrogen, usually 100 p.g of ethinyl estradiol, given over a period of 14 to 16 days followed by 5 days of a progestin. It is quite important to provide for prompt development of secondary sex characteristics. The prompt appearance of breast buds and improvement in growth of pubic hair are reassuring signs to these usually timid, withdrawn children. Many of these children are quite shy and withdrawn until one brings about the development of a physiologic puberty. At that time their personalities change dramatically and they become much more outgoing and exhibit extrovert tendencies. However, development of secondary sex characteristics brings about a concern for future linear growth. We do not believe that anabolic agents are of any value in increasing the final resultant height of these patients. There is no good evidence to support the hypothesis that these patients are deficient in pituitary growth hormone. Attempts to treat these patients with pituitary growth hormone have met with rather equivocal results. Their ability to release growth hormone upon hypoglycemic provocation appears to be normal. It is a common piece of misinformation that many of these children suffer from some degree of mental retardation. In conjunction with our Psychological Center at the University of Georgia, we have performed rather extensive psychological and psychometric evaluation of patients with gonadal dysgenesis. Our evaluations to date seem to indicate that these patients indeed have a normal verbal intelligence and a slightly less than normal nonverbal intelligence on standard psychometric tests. This applies to all of our patients with gonadal dysgenesis except those with XY gonadal dysgenesis, who seem to have a male type of psychometric pattern. We have a considerable number of patients with gonadal dysgenesis who are college graduates. It is only in rare instances that we see patients in our Growth and Genetics Clinic with gonadal dysgenesis who have severe mental retardation. These patients are invariably of the 45,XO sex chromosome constitution.
Tumor in the Ridge With respect to follow-up, the principal concern is observation of the patient for any evidence of neoplastic tumor of the ridge. The important diagnostic steps are a careful pelvic examination and a periodic anteroposterior film of the pelvis, looking for evidence of calcification in the region of the rudimentary streak. If a mass is palpable or calcification is evident on roentgenogram, then exploration is performed and usually if the rudimentary streaks are extirpated we will perform a hysterectomy in the older girl. Obviously, the question of hysterectomy has to be discussed in considerable detail with the patient, and if there is any psychic need for cyclic menses then hysterectomy is not performed. The advan-
tage of hysterectomy is that it permits one to use larger doses of estrogens for whatever value they may have in preventing the osteoporosis which these patients have early in life and which seems to progress throughout life. There have been only one or two reported instances of adenocarcinoma of the uterus occurring in patients with rudimentary streak gonads who have been on estrogen substitution therapy. As advances in cytogenetics continue, especially fluorescent monitoring and other types of methodology to study chromosomes, we can expect that the heterogenous nature of gonadal dysgenesis will continue to become more widely recognized. More and more, this disorder may be found to be responsible for cases of primary amenorrhea regardless of the appearance of the patient. At present we may even say that this disorder may be found as a responsible agent in many instances of secondary amenorrhea. I believe that in the future, with advances in cytogenetics and more liberal use of the laparoscope, that gonadal dysgenesis will be uncovered as the culprit in most patients with primary gonadal failure.
REFERENCES 1. Bahner, F., Schwartz, G., Heinz, H. A., et al.: Turner's syndrome with fully developed secondary sex characteristics and fertility. Acta. Endocrinol. (Kobenhaun), 35:379, 1960. 2. Espiner, E. A., and Veal, A. M. D., et al.: Familial syndrome of streak gonads and normal male karyotype in five phenotypic females. New Eng. J. Med., 283:6, 1970. 3. Ford, C. E., Jones, K. W., Polani, P. E., et al.: A sex chromosome anomaly in a case of gonadal dysgenesis (Turner's syndrome). Lancet, 1 :711, 1959. 4. Greenblatt, R B., Byrd, J. R, McDonough, P. G., et al.: The spectrum of gonadal dysgenesis. Amer. J. Obstet. Gynec., 98:151, 1967. 5. Grumbach, M. M., Van Wyck, J. J., and Wilkins, L.: Chromosomal sex in gonadal dysgenesis (ovarian agenesis): Relationship to male pseudohermaphroditism and theories of human sex differentiation. J. Clin. Endocrinol., 15:1161, 1955. 6. Jost, A.: Recherches sur la differenciation sexuelle de l'embryon de Lapin. Compt. Rend. I'Assoc. Anat., 34:225, 1947. 7. Judd, H. L., Scully, R E., Atkins, L., Neer, R M., and Kliman, B.: Pure gonadal dysgenesis with progressive hirsutism. New Eng. J. Med., 282:881, 1970. 8. McDonough, P. G., Byrd, J. R and Freedman, M. A.: Gonadal dysgenesis with ovarian function: Clinical and cytogenetic findings in six patients. Obstet. Gynec., 37:868, 1971. 9. McDonough, P. G., Byrd, J . .R., and Mahesh, V. B.: Gonadal dysgenesis with spontaneous menses: Report of a patient stimulated with HMG and HCG. Fertil. Steril., 20:451,1969. 10. McDonough, P. G., Greenblatt, R B., Byrd, J. R, and Hastings, E. V.: Gonadoblastoma (Gonocytoma III): Report of a case. Obstet. Gynec., 29:54, 1967. 11. McDonough,P. G., Mahesh, V. B. and Byrd, J. R: The diagnostic use of gonadotropins. Fertil. Steril., 21 : 126, 1970. 12. McDonough, P. G., and Simmons, R G.: Pelvic pneumoperitoneum in intersex disorders: Asymmetrical gonadal dysgenesis. Obstet. Gynec., 37:368, 1971. 13. Nakashima, I., and Robinson, A.: Fertility in a 45,X female, Pediatrics, 47:770, 1971. 14. Schellhas, H. F., Trujillo, J. M., Rutledge, F. N., and Cork, A.: Germ cell tumors associated with XY gonadal dysgenesis. Amer. J. Obstet. Gynec., 109:1197,1971. 15. Singh, R P., and Carr, D. H.: The anatomy and histology of XO human embryos and fetuses. Anat. Rec., 155:369, 1966. 16. Turner, H. H.: A syndrome of infantilism, congenital webbed neck and cubitus valgus. EndOCrinology, 23:566, 1938. Medical College of Georgia Augusta, Georgia 30902